Saving seeds - in four million years we'll laugh about it!

Here comes a slightly different 'Seed of the Month' blog by the Millennium Seed Bank's Seed Morphologist, Wolfgang Stuppy, in which he explains why saving seeds is more than just a good idea!

This is not a regular ‘Seed of the Month’ blog post. Rather than writing about the seeds of a particular plant, I decided that this time, I want to share my ideas of the ‘bigger picture’ with you, which lays bare the ultimate reason why we, here at Kew’s Millennium Seed Bank, are so passionate about saving seeds from all over the world. The following ‘essay’ is about life on Earth, the future of mankind and the true relevance of seeds. And so here it goes...

Science, washing powder and beyond

When scientists are lost for words they create technical terms which help them to communicate with each other more easily and precisely. Most of these technical terms don’t ever percolate into the public domain. However, nowadays everybody talks about biodiversity - some still think it’s a new kind of washing powder. But behind this abstract word lies a meaning that goes far beyond that of washing powder, in fact, far beyond anything anyone can imagine.

A (very!) small selection of fruits and seeds from all over the world [Images from ’SEEDS – Time Capsules of Life’ by Rob Kesseler & Wolfgang Stuppy and ‘FRUIT – Edible, Inedible, Incredible’ by Wolfgang Stuppy & Rob Kesseler; Copyright Papadakis Publisher, Newbury, UK]

All creatures great and small

‘Biodiversity’ refers to the cornucopia of all life forms on Earth, most of which are still unknown to us. Estimates range from 3 million to 100 million species. A smart scientific study from 2011claims to have calculated that there are altogether almost 9 million species of plants, animals, fungi, bacteria and so-called protists (= microscopic critters that are neither plants, animals, fungi or bacteria). Of all these, only about 1.2 million are known to science and formally described. As for the other 8 million or so species, we kind of know that about 6.5 million of them are animals (mostly very small ones) but we don’t yet know who they are.

Kingdom of plants

After animals, the second largest kingdom of life on Earth are plants. At about 300,000 to 450,000 species, there are a lot less of them than animals but that doesn’t mean that they are less important. Quite the contrary! Many of us love plants, due to their sheer omnipresence, most of us can’t but take them for granted. But when we stop and think for a moment, I mean really think, plants, even the scruffiest of weeds, are amazing. Actually, they are not only amazing, they are, in fact, our life support system.

Unlike animals, plants have the remarkable ability to use sunlight to make sugar from just water and carbon dioxide during a complicated process called ‘photosynthesis’. In doing so, they not only produce their own food but also feed – either directly or indirectly – literally all life on Earth. Furthermore, as a ‘waste product’ of photosynthesis, they produce the oxygen in our atmosphere. To put it simply, without plants we would neither be able to breathe nor eat.

What’s the point of biodiversity?

Good question. Why would we need so many species if we don’t even know most of them? Let me try to illustrate this point using a not too far-fetched allegory.

Imagine your continued existence depends on a complicated life support system which, should it fail, would mean that you are definitely going to die. Scary stuff! Now imagine that your life support system is a very large, robust and luxurious one, one that has built in a great deal of redundancy and backup systems. This means that if one or several parts fail or break, there are plenty of other parts which can make up for the failure without you even noticing. Phew! Not too much to worry about then. In fact, you can almost forget that you are on a life support system. After all, it’s so huge and so fail-safe that you might take it for granted as much as the sun that rises every morning. And because it’s so huge and apparently so fail-safe, you probably think it’s no harm to make it a bit smaller by getting rid of some parts. After all, by making it smaller you can create more room for other important things, such as growing food to feed your family or to earn money (preferably lots of it!). Now imagine this huge and ever so reliable life support system is not a metal box with loads of man-made parts inside but a living system that consists of all the plant species on Earth as well as all the other organisms which, although they also depend on plants, still play important regulatory roles.

Welcome to reality!

If you manage to take this imaginary step you have actually crossed from my very simple allegory into real life. By turning ever more ‘wild’ places like tropical rainforests into ‘cultivated’ land for agriculture, mines, factories, housing and so on, to produce ever more stuff for ever more people, we are causing the extinction of countless species. This extermination of species – unintended or not - is equivalent to the dismantling of our life support system which we can now give a name. It is actually called ‘biodiversity’.

Although ‘biodiversity’ is very robust and can cope with severe losses, there comes a point when it begins to ‘malfunction’ and finally fail if too many parts are removed. Here's a good analogy: remove part after part from your car until it stops working. You will find that some parts will make hardly any difference if they are missing, others will be crucial for the running of the engine and the turning of the wheels. It is just that nature is far more complicated than even the most sophisticated car and there are no mechanics out there who know exactly how to fix it.

A slab with plant fossils on display at the Canterbury Museum in Christchurch, New Zealand. These specimens belong to a mix of flowering plants, podocarps (a kind of conifer) and cycads, and are about 100 million years old (Photo: Wolfgang Stuppy)

Species have always come and gone in the Earth’s history, as we can tell from all the million-year-old fossils of strange-looking animals and plants displayed in museums. Even though it is true that extinction is a natural process, the current rate of extinction is about 1,000 times greater than the natural rate and this is solely due to human activities. Compared to the alarming loss of species, climate change, although currently dominating the media, is only the bitter ‘icing on the cake’.

Forever is not for ever – or is it?

Extinction of a species is forever. Each species that disappears takes with it one elaborate piece of our vast and complicated life support system, which itself is the result of millions of years of evolution. Tragically, on top of this, the extinction of a species also affects many other species with which it has shared the same environment for thousands if not millions of years. The fossil record tells us that life on Earth has already experienced five global mass extinctions.

After each disaster the recovery of global biodiversity took between four and twentymillion years. Four million years at least! Nobody can imagine such a vast amount of time! To illustrate the dimensions, modern humans like us, have existed for no longer than about two hundred thousand years. It is pretty clear that we can’t wait for biodiversity to restore itself. For us, the vast geological time spans involved in the evolution of life mean that with every species that we lose, we lose a part of our life support system – forever!

Why saving seeds is more than just a good idea

At this point it is worth remembering that plants are the only solar-powered primary producers, and, as such, support literally all other life on Earth. Because of their crucial importance, one trait of plants almost seems like a miraculous gift to mankind: their ability to produce seeds.

Unlike animals, most plants (apart from algae, mosses, ferns and other spore plants) can survive extensive periods of unfavourable conditions in the form of seeds. As long as they are kept dry, seeds can hold a tiny plant safe and alive (albeit in a quiet, coma-like state) inside their hard shell for years, decades, centuries or even millennia.

A typical seed with the tiny green baby plant sheltered in its centre. This particular seed belongs to the South African gifboom ('poison tree'; Hyaenanche globosa, Picrodendraceae) (Photo: Elly Vaes)

The ability of seeds to survive for long periods of time in the dry state is their most astonishing and momentous quality. Above all, it holds the key to the survival of a species! And this is exactly what we, Kew’s Millennium Seed Bank Partnership, are capitalising on. Because of their small size and longevity, seeds provide an extremely efficient means of saving species from extinction. Rather than accepting the fact that we will lose thousands of unique species of plants in the years to come, we make every effort to collect their seeds now in order to ensure their survival in the future. Saving seeds is the best chance we have to enable us to re-build essential parts of our life support system, should it eventually begin to fail.

To date, the Millennium Seed Bank Partnership has managed to collect the seeds of 10% of all plant species (c. 32,000 species). Until 2020, we aim to collect the seeds of 25% (75,000 species) of the world’s plant species. If you agree that seed conservation is a good idea you can help us achieve our goal by adopting a seed for £25 or saving an plant species outright.

A ‘cool view’ of the cold storage at the Millennium Seed Bank (Photo: Wolfgang Stuppy)

Comments

Wolfgang

21 January 2013

Comment:

Hi Andrea,
thanks for your comment. It is true that the over seventy thousand species of algae are no longer considered as plants and some former single-celled 'algae', such as Euglena, are nowadays classified as protists. Also, cyanobacteria ('blue-green algae') are capable of photosynthesis, too, but they are procaryotic organisms. Perhaps I was a bit too simplistic in trying to keep the story clear and simple. After all, marine algae produce a significant amount of the oxygen we breathe. However, to explain all the intricacies of the classification of photoautotrophic organisms would have made the story more complicated, in a way, unnecessarily so. After all, imagine a world without plants. A reduced human population might still be able to breathe and eat, if only algae and animals living directly or indirectly off them - but what kind of life would that be?

Great post Wolfgang!
Had to share it.
Greetings for a wonderful 2013 to you and all at the MSB!
Currently taking in the fact our Bureau of Meteorology has added another colour to the temperature map of OZ!
cheers,
Sophie